nova_70_383 wrote:dont rule out bad gas... i have got 4 bad tanks now... very frustrating... seem to work fine at first untill you get to a certain pressure then the crap hits the fan.
Buggy Chief
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so being a novice and knowing enough to be dangerous...Will Airgas give a refund or credit if gas is bad?
nova_70_383
- nova_70_383
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im sure each place may treat the situation differently. my air gas had the tank tested and found contamination and gave me a free tank. i had two previous tanks that were bad but didnt figure it out untill the 3rd. they gave me a free tank because of it. that was quite a while back. then about a month ago i got another tank that was not good half way through it. i brought it in and requested it get tested. they gave me a full one in place no questions asked. i think they are being good about this. others may not agree. still have not heard what they found on the last tank as of yet.
- Braehill
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@ Minn. Dave,
If a cylinder can't adsorb moisture at 1000# psig then how do you explain me filling a trailer of hydrogen to 2400+ lbs. of pressure with a -120 dew point or .25 PPM moisture and it returning at 500 lbs. and a dew point of -50 or 67 PPM of moisture. It happens all day every day and I have 4 large file cabinets of records to prove it. That's with trailers that are leak checked every time they're filled.
As your pressure drops you are constantly moving towards the gases saturation point until you get below 1 Atm. then you start going the other way.
It's not likely that anybody welding would ever pick up the difference between .25PPM and 67PPM's of moisture in a normal setting.
I'm not even saying that his problem is the moisture being adsorbed from the atmospere, but probably from a poor clean up of the cylinder at the fill plant or any of the problems inherent to it being a multiprocess machine.
Len
If a cylinder can't adsorb moisture at 1000# psig then how do you explain me filling a trailer of hydrogen to 2400+ lbs. of pressure with a -120 dew point or .25 PPM moisture and it returning at 500 lbs. and a dew point of -50 or 67 PPM of moisture. It happens all day every day and I have 4 large file cabinets of records to prove it. That's with trailers that are leak checked every time they're filled.
As your pressure drops you are constantly moving towards the gases saturation point until you get below 1 Atm. then you start going the other way.
It's not likely that anybody welding would ever pick up the difference between .25PPM and 67PPM's of moisture in a normal setting.
I'm not even saying that his problem is the moisture being adsorbed from the atmospere, but probably from a poor clean up of the cylinder at the fill plant or any of the problems inherent to it being a multiprocess machine.
Len
Now go melt something.
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Len
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Len
- MinnesotaDave
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Hey Len, I agree with this last statement of yours. The other stuff I have no knowledge of the subject.Braehill wrote:@ Minn. Dave,
I'm not even saying that his problem is the moisture being adsorbed from the atmospere, but probably from a poor clean up of the cylinder at the fill plant or any of the problems inherent to it being a multiprocess machine.
Len
I maintain, in my limited understanding of the world, that moisture, at 1 ATM, does not enter into a highly pressurized vessel.
I could be wrong, have been before, but if there was an opening to the outside the argon would escape.
If I understand part of your other statements, as the argon is used the moisture that is already in the tank is now a higher % in relation to the argon that is left. Is that what you said? Sounds pretty reasonable to me.
Dave J.
Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~
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Tried being normal once, didn't take....I think it was a Tuesday.
Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~
Syncro 350
Invertec v250-s
Thermal Arc 161 and 300
MM210
Dialarc
Tried being normal once, didn't take....I think it was a Tuesday.
GreinTime
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He's not saying that there is a hole leading to the outside friend, rather he's saying that steel is porous enough that water/moisture can work its way through the steel using capillary attraction at any pressure. He can get crazy technical with this (believe me, I know, its lead to some interesting dinner conversations over the years.) But the bottom line is unless they vacuum your bottle to at least 28 in/hg (Common figure for moisture removal in an automotive HVAC capacity) you are going to have compounding moisture problems after a few times of getting your bottle refilled.
Also, it would take them forever to fill your bottle if they vac'd it every time, as we held vacuum for 30 minutes minimum while sucking cars down. Say you have 100 ppm of moisture left in your bottle when you get it. If they don't vacuum it down when you need it refilled, now you have 200 ppm, and so on an so forth.
This definitely leads to problems after a few times, especially if you just rent the bottle and they swap it out (most people don't know any better, and waste countless hours trying to diagnose a bad bottle of gas. Most loading dock gas company workers could care less, as its job security for them, and they probably get a laugh out of it!
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Also, it would take them forever to fill your bottle if they vac'd it every time, as we held vacuum for 30 minutes minimum while sucking cars down. Say you have 100 ppm of moisture left in your bottle when you get it. If they don't vacuum it down when you need it refilled, now you have 200 ppm, and so on an so forth.
This definitely leads to problems after a few times, especially if you just rent the bottle and they swap it out (most people don't know any better, and waste countless hours trying to diagnose a bad bottle of gas. Most loading dock gas company workers could care less, as its job security for them, and they probably get a laugh out of it!
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#oneleggedproblems
-=Sam=-
-=Sam=-
I had the same exact problem !! My tank reached 1000 PSI I changed the gauage and it was still 1000 PSI. During welding I got sparks that ruined my new cup and I got realy bad burned welds. Torch almost turned into a plasma cutter during welding.
I wonder if the company ripped me off by adding air to tank and then argon. Argon is light so was on top until it reached 1000 PSI. I bought another one from the same vendor. I emptied the first completely when I turned it in. Please help advise. I am a beginner as well. I have two tig welders and both did the same.
I wonder if the company ripped me off by adding air to tank and then argon. Argon is light so was on top until it reached 1000 PSI. I bought another one from the same vendor. I emptied the first completely when I turned it in. Please help advise. I am a beginner as well. I have two tig welders and both did the same.
noddybrian
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No offense but I kinda doubt that - argon is heavier than air & would have mixed with whatever else was in or added to the bottle - whatever problem you encountered there has to be a more logical explanation - maybe post any relevant facts & someone here will get to the issue for you.
PS. Welcome to the forum.
PS. Welcome to the forum.
Not only that, gases are just that---gases. Doesn't matter if there is 99% argon/1% air or 1%argon/99%air, they are always in constant motion and always mixed homogeneously. Liquids on the other hand are subject to gravity and their corresponding specific densities affect their buoyancy. Another way to think about it is thinking about "mig gases", such as 75%Ar/25%CO2. CO2 is denser than Argon, but never has Argon "floated" to the top of a 75/25 Ar/CO2 tank. Again, that only applies to liquids.noddybrian wrote:No offense but I kinda doubt that - argon is heavier than air & would have mixed with whatever else was in or added to the bottle - whatever problem you encountered there has to be a more logical explanation - maybe post any relevant facts & someone here will get to the issue for you.
PS. Welcome to the forum.
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This applies to fluids.
Liquids and gasses are both fluids, and will demonstrate some segregation in an undisturbed environment. Yes, heat (read kinetic energy) keeps them mixed, but not homogenously. The lighter gas will be more concentrated at the top. That's why the oxygen level on Mt. Everest falls below the danger level. If the atmosphere were homogenous, climbers wouldn't need supplemental oxygen.
What changes with bottle pressure is dewpoint, the amount of moisture a gas can contain.
I'd have to go back to college physics to give a full explanation, but there's enough anecdotal evidence to support the idea that moisture problems become more obvious as bottle pressure drops.
Steve S
Liquids and gasses are both fluids, and will demonstrate some segregation in an undisturbed environment. Yes, heat (read kinetic energy) keeps them mixed, but not homogenously. The lighter gas will be more concentrated at the top. That's why the oxygen level on Mt. Everest falls below the danger level. If the atmosphere were homogenous, climbers wouldn't need supplemental oxygen.
What changes with bottle pressure is dewpoint, the amount of moisture a gas can contain.
I'd have to go back to college physics to give a full explanation, but there's enough anecdotal evidence to support the idea that moisture problems become more obvious as bottle pressure drops.
Steve S
While I agree with you, that is not happening in a tank of welding gas where the altitude difference between the bottom of the tank and the top of it will cause a meaningful segregation of the gases inside---if that was the case welders everywhere would be having issues with 75/25 mig gas. If your tank was a couple of miles tall, THEN I could see some argon shifting to one end of the cylinder with the presence of another substance inside, creating a buoyancy effect.Otto Nobedder wrote:This applies to fluids.
Liquids and gasses are both fluids, and will demonstrate some segregation in an undisturbed environment. Yes, heat (read kinetic energy) keeps them mixed, but not homogenously. The lighter gas will be more concentrated at the top. That's why the oxygen level on Mt. Everest falls below the danger level. If the atmosphere were homogenous, climbers wouldn't need supplemental oxygen.
What changes with bottle pressure is dewpoint, the amount of moisture a gas can contain.
I'd have to go back to college physics to give a full explanation, but there's enough anecdotal evidence to support the idea that moisture problems become more obvious as bottle pressure drops.
Steve S
My post was not to discredit any ideas about moisture problems becoming more prevalent in certain situations, it was only to support the fact that under normal circumstances, the gases inside a normal cylinder will not cause meaningful separation where one gas becomes significantly collected on one end of a welding tank. No need to "go back to college physics" here. My BSc reads "Mathematics/Physics".
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Fair enough, Oscar.
It was not my intent to suggest that segregation was the cause of the problem; Just over-analyzing, since you implied gasses and liquids behave differently. Gasses and liquids are both fluids and behave the same (though on different scales).
I can, in fact, demonstrate gas segregation in a measurable way using Helium and Argon, but the measurements amount to ppm differences which one would not notice while welding.
However, the moisture issue is a distinct possibility. The effects of temperature and pressure can be read each day on the weather report, in "relative humidity".
Steve S
It was not my intent to suggest that segregation was the cause of the problem; Just over-analyzing, since you implied gasses and liquids behave differently. Gasses and liquids are both fluids and behave the same (though on different scales).
I can, in fact, demonstrate gas segregation in a measurable way using Helium and Argon, but the measurements amount to ppm differences which one would not notice while welding.
However, the moisture issue is a distinct possibility. The effects of temperature and pressure can be read each day on the weather report, in "relative humidity".
Steve S
Did Buggy Chief find the leak that was sucking oxygen into the stream of his argon yet?
Did he get the liquid dishsoap, a cheap paint brush, and a water bottle cut in half (to hold a few drops of liquid dishsoap and water mix) and do the complete system bubble leak test yet? My guess is on the torch, perhaps the white cup sealer, or perhaps a loose connection under the handle cover.
--zip.
Did he get the liquid dishsoap, a cheap paint brush, and a water bottle cut in half (to hold a few drops of liquid dishsoap and water mix) and do the complete system bubble leak test yet? My guess is on the torch, perhaps the white cup sealer, or perhaps a loose connection under the handle cover.
--zip.
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I have a #17 air-cooled torch at the moment. I too would have problems with the arc sputtering. I eventually found out what was going on in my case. Right where the gas hose enters the torch body at the end of the handle, I managed to pinch off the gas hose by how I was sometimes holding the torch while welding; shutting off my source of shielding gas.